<template>
    <fieldset>
        <legend>vue3的选项式methods</legend>
        <button>-</button>
        <b>{{ num }}</b>
        <button @click="increase">+</button>
    </fieldset>
</template>
<script setup>
import { ref } from "vue"
let num = ref(10)
let increase = function () {
    num.value++
}

</script>